Changes in the three-dimensional organization of LoVo cells associated with resistance to doxorubicin

LoVo cells and a derived subline resistant to doxorubicin were compared in the spheroids system. The resistant line, unlike the parent one, was unable to grow as spheroids, but formed irregular loose aggregates. Moreover treatment of the resistant cells with membrane-active agents able to reverse pleiotropic drug resistance had no effect on the capability of these cells to grow as spheroids. The results indicate that the inability of resistant cells to form spheroids is not related to the resistance mechanism.     

Possible pro-arrhythmic effects of vagal stimulation maneuvers

Vagal stimulation manoeuvres are currently used in clinical practice both for diagnostic and therapeutic purposes. Such manoeuvres are not, however, without risk. The Authors describe the case of a patient in whom, in the past, a Lown-Ganong-Levine syndrome had been diagnosed. During a vagal stimulation, performed because of a suspected paroxysmal supraventricular tachycardia crisis, a sudden increase of ventricular rate, up to 280 b/min, occurred. At the end of this paroxysm, the presence of an atrial flutter was ascertained. The high ventricular rate was thus attributed to an 1:1 A-V conduction which occurred because of the performed manoeuvres. The possibility of causing not only hypokinetic but also potentially dangerous hyperkinetic arrhythmias must be held in consideration; the vagal stimulation manoeuvres therefore should not be performed without the possibility of electrocardiographic monitoring.     

Outcome of criminal investigation into allegations of sexual abuse

The aim was to study the outcome of criminal investigation into allegations of sexual abuse made by 160 children assessed over a two year period in a specialist paediatric unit in the North of England. In all, 141 of the 160 children (88%) were female, and 99 (62%) were aged under 12 years. There were 145 males and nine females named by children in allegations of sexual abuse. Fathers formed the largest single group of alleged male perpetrators (56/176). None of the nine alleged female abusers was prosecuted. Of the 145 males, 57 reached trial; 49 were convicted, an 86% conviction rate of those sent to trial and a rate of proven sexual offence (including cautions) of 44% (54/124) among men originally interviewed by the police. Twenty five per cent of children (17/68) who could have testified did so, most giving evidence against someone who was known to them. Pragmatic selection of cases for prosecution resulted in an outcome highly vindicating of the decision to prosecute. The possible effects of this process are discussed.     

Diverse effects of natural antioxidants on cyclosporin cytotoxicity in rat renal tubular cells.

BACKGROUND: As is well known, the use of the immunosuppressive drug cyclosporin A (CsA) is partially restricted by its nephrotoxic effects, which include early changes in haemodynamics followed by irreversible injuries to the renal tubules. Although the mechanisms responsible for these side effects are poorly understood, an involvement of reactive oxygen species (ROS) has been suggested. In this study, we selected three natural antioxidants, resveratrol, hydroxytyrosol and vitamin E, on the basis of their scavenging capabilities, and tested their protective effects against CsA toxicity. METHODS: Immortalized rat tubular cells (RPTc) were used as the model system. Cell viability was checked with trypan blue assay, and free radical formation was measured using the fluorescent probe 2,7-dichlorofluorescein (DCF). We evaluated several oxidative stress parameters, including phospholipid peroxidation products, glutathione levels and oxygenase expression. RESULTS: Incubation of RPTc with 25 muM CsA induced a significant decrease in cell viability paralleled by intracellular ROS formation and alterations in lipid peroxidation. There was also an imbalance of glutathione redox state as well as upregulation of heme oxygenase-1 (HO-1). The three antioxidants, at micromolar concentration, quantitatively prevented the ROS-activated DCF fluorescent signal and membrane lipid peroxidation. Both hydroxytyrosol and resveratrol strengthened the CsA induction of HO-1 expression. Moreover, vitamin E and resveratrol counteracted CsA-induced changes in the glutathione redox state via different mechanisms, whereas hydroxytyrosol was completely ineffective. Similarly, CsA-dependent nephrotoxicity was prevented by vitamin E, while resveratrol only exerted partial protection, and hydroxytyrosol showed no protective effects. CONCLUSION: Our results indicate that the diverse cytoprotective effects of the antioxidants tested in these studies were not directly related to their scavenging capabilities. These findings confirm a key role for glutathione in protecting cells from CsA-induced adverse effects and do not support a direct link between CsA-mediated ROS generation and adverse renal effects.     

甘油果糖对人RBC、大鼠RBC的作用及输液安全性的研究

目的:探讨甘油果糖注射液(Glycerol and Fructose Injection)对人红细胞(Red blood cell,RBC),大鼠RBC的作用及对大鼠输液安全性的研究,以指导临床应用。方法:以40例健康成人RBC、32只sD大鼠RBC为研究对象,进行体外溶血试验;以72只SD大鼠为研究对象,进行输液安全性研究,研究组为甘油果糖注射液,对照组为生理盐水注射液,应用改良酸化甘油溶解实验测定甘油果糖注射液对人RBC和大鼠RBC的溶解程度,应用邻-甲联苯胺氧化显色法测定甘油果糖注射液对上清液游离血红蛋白(Hemoglbin,HB)含量的影响。同时测定研究组和对照组大鼠血浆游离HB、蛋白非结合胆红素(间接胆红素)、尿素氮(Blood urea nitrogen,BUN)、肌酐的含量,以对甘油果糖注射液安全性进行研究。结果:体外试验为甘油果糖注射液对人RBC和大鼠RBC的溶解程度与生理盐水相似,对上清液游离HB含量无明显影响。对大鼠给予甘油果糖注射液和生理盐水,最快输液速度6ml/min和最大输液量30ml/kg/d,24小时后测定大鼠血浆游离HB、蛋白非结合胆红素、BUN、肌酐的含量,两组结果相似。结论:甘油果糖注射液在体外对人RBC和大鼠RBC无明显溶解作用。在大鼠体内也没有发现有溶血作用,对肾脏功能影响与生理盐水相似。     

Detection of TP53 mutation, loss of heterozygosity and DNA content in fine-needle aspirates of breast carcinoma.

Recent preclinical and clinical data suggest that TP53 status and TP53 mutations may be important in determining tumour aggressiveness and therapy response. In this study we investigate the feasibility of a structural and quantitative analysis of TP53 on fine-needle aspiration (FNA) material obtained from 31 consecutive female patients with breast carcinoma, enrolled in a primary chemotherapy protocol. Tumours were screened for p53 protein overexpression and TP53 mutations (exons 5-8) using immunocytochemistry, polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and DNA sequencing analyses, and finally using fluorescence in situ hybridization (FISH) analysis. Positive nuclear staining was identified in six cases whereas mutations were detected in nine. Although the immunoreactive pattern fitted fully with the characterized TP53 mutation type, the considerable number of null p53 mutations (i.e. four) coupled with the lack of information regarding the localization of TP53 mutations make immunocytochemistry an inadequate indicator of TP53 function deregulation. Combining molecular and FISH analyses, we detected three cases with TP53 deletion and one case with deletion and mutation. Finally, DNA static-image analysis performed on 29 cases showed aneuploidy in 26 cases, which included all TP53-mutated cases. The present results show that FNA may assist clinical decisions by allowing the evaluation of a variety of biological parameters relevant for prognosis and treatment planning.